On Wed, Sep 7, 2016 at 9:13 AM, Andrew Purtell <apurt...@apache.org> wrote:
> We shouldn't admit half baked changes that won't be finished. However in > this case the crew working on this feature are long timers and less likely > than just about anyone to leave something in a half baked state. Of course > there is no guarantee how anything will turn out, but I am willing to take > a little on faith if they feel their best path forward now is to merge to > trunk. I think this is a very good point that Andrew raised. The developers have no intention to stop working on improvements after the merge. Likely that the stabilization and working on remaining phase 3/4 items will continue for the next months to come. If we can get a commitment that any remaining issues will be addressed by end-of-year timeframe, then making a call for the merge and inclusion in hbase-2.0 will become much easier. > I only wish I had bandwidth to have done some real kicking of the > tires by now. Maybe this week. > > (Yes, I'm using some of that time for this email :-) but I type fast.) > > That said, I would like to agitate for making 2.0 more real and spend some > time on it now that I'm winding down with 0.98. I think that means > branching for 2.0 real soon now and even evicting things from 2.0 branch > that aren't finished or stable, leaving them only once again in the master > branch. Or, maybe just evicting them. Let's take it case by case. > > I think this feature can come in relatively safely. As added insurance, > let's admit the possibility it could be reverted on the 2.0 branch if folks > working on stabilizing 2.0 decide to evict it because it is unfinished or > unstable, because that certainly can happen. I would expect if talk like > that starts, we'd get help finishing or stabilizing what's under discussion > for revert. Or, we'd have a revert. Either way the outcome is acceptable. > > > On Wed, Sep 7, 2016 at 8:56 AM, Dima Spivak <dimaspi...@apache.org> wrote: > > > I'm not sure that "There is already lots of half-baked code in the > branch, > > so what's the harm in adding more?" is a good code commit philosophy for > a > > fault-tolerant distributed data store. ;) > > > > More seriously, a lack of test coverage for existing features shouldn't > be > > used as justification for introducing new features with the same > > shortcomings. Ultimately, it's the end user who will feel the pain, so > > shouldn't we do everything we can to mitigate that? > > > > -Dima > > > > On Wed, Sep 7, 2016 at 8:46 AM, Vladimir Rodionov < > vladrodio...@gmail.com> > > wrote: > > > > > Sean, > > > > > > * have docs > > > > > > Agree. We have a doc and backup is the most documented feature :), we > > will > > > release it shortly to Apache. > > > > > > * have sunny-day correctness tests > > > > > > Feature has close to 60 test cases, which run for approx 30 min. We > can > > > add more, if community do not mind :) > > > > > > * have correctness-in-face-of-failure tests > > > > > > Any examples of these tests in existing features? In works, we have a > > clear > > > understanding of what should be done by the time of 2.0 release. > > > That is very close goal for us, to verify IT monkey for existing code. > > > > > > * don't rely on things outside of HBase for normal operation (okay for > > > advanced operation) > > > > > > We do not. > > > > > > Enormous time has been spent already on the development and testing the > > > feature, it has passed our internal tests and many rounds of code > reviews > > > by HBase committers. We do not mind if someone from HBase community > > > (outside of HW) will review the code, but it will probably takes > forever > > to > > > wait for volunteer?, the feature is quite large (1MB+ cumulative patch) > > > > > > 2.0 branch is full of half baked features, most of them are in active > > > development, therefore I am not following you here, Sean? Why > HBASE-7912 > > is > > > not good enough yet to be integrated into 2.0 branch? > > > > > > -Vlad > > > > > > > > > > > > > > > > > > On Wed, Sep 7, 2016 at 8:23 AM, Sean Busbey <bus...@apache.org> wrote: > > > > > > > On Tue, Sep 6, 2016 at 10:36 PM, Josh Elser <josh.el...@gmail.com> > > > wrote: > > > > > So, the answer to Sean's original question is "as robust as > snapshots > > > > > presently are"? (independence of backup/restore failure tolerance > > from > > > > > snapshot failure tolerance) > > > > > > > > > > Is this just a question WRT context of the change, or is it means > > for a > > > > veto > > > > > from you, Sean? Just trying to make sure I'm following along > > > adequately. > > > > > > > > > > > > > > > > > > I'd say ATM I'm -0, bordering on -1 but not for reasons I can > > articulate > > > > well. > > > > > > > > Here's an attempt. > > > > > > > > We've been trying to move, as a community, towards minimizing risk to > > > > downstream folks by getting "complete enough for use" gates in place > > > > before we introduce new features. This was spurred by a some features > > > > getting in half-baked and never making it to "can really use" status > > > > (I'm thinking of distributed log replay and the zk-less assignment > > > > stuff, I don't recall if there was more). > > > > > > > > The gates, generally, included things like: > > > > > > > > * have docs > > > > * have sunny-day correctness tests > > > > * have correctness-in-face-of-failure tests > > > > * don't rely on things outside of HBase for normal operation (okay > for > > > > advanced operation) > > > > > > > > As an example, we kept the MOB work off in a branch and out of master > > > > until it could pass these criteria. The big exemption we've had to > > > > this was the hbase-spark integration, where we all agreed it could > > > > land in master because it was very well isolated (the slide away from > > > > including docs as a first-class part of building up that integration > > > > has led me to doubt the wisdom of this decision). > > > > > > > > We've also been treating inclusion in a "probably will be released to > > > > downstream" branches as a higher bar, requiring > > > > > > > > * don't moderately impact performance when the feature isn't in use > > > > * don't severely impact performance when the feature is in use > > > > * either default-to-on or show enough demand to believe a non-trivial > > > > number of folks will turn the feature on > > > > > > > > The above has kept MOB and hbase-spark integration out of branch-1, > > > > presumably while they've "gotten more stable" in master from the odd > > > > vendor inclusion. > > > > > > > > Are we going to have a 2.0 release before the end of the year? We're > > > > coming up on 1.5 years since the release of version 1.0; seems like > > > > it's about time, though I haven't seen any concrete plans this year. > > > > Presuming we are going to have one by the end of the year, it seems a > > > > bit close to still be adding in "features that need maturing" on the > > > > branch. > > > > > > > > The lack of a concrete plan for 2.0 keeps me from considering these > > > > things blocker at the moment. But I know first hand how much trouble > > > > folks have had with other features that have gone into downstream > > > > facing releases without robustness checks (i.e. replication), and I'm > > > > concerned about what we're setting up if 2.0 goes out with this > > > > feature in its current state. > > > > > > > > > > > > > -- > Best regards, > > - Andy > > Problems worthy of attack prove their worth by hitting back. - Piet Hein > (via Tom White) >
